In the prior art, several implantation devices for humans or animals are known. The implants at least partly create positive-fit connections to human or animal tissue parts, particularly to skeletal parts such as bones. Therein, the implants may help to connect tissue parts together or they may help to connect tissue parts to other means supporting or replacing tissue parts or to other therapeutic auxiliary devices.
Known implants for creating connections to skeletal parts include screws, pins, staples, etc. for connecting one bone to another bone or for connecting a bone to artificial carrying, stabilizing or supporting parts or to parts replacing skeletal parts such as stabilization or fixation plates, wires, artificial joint elements, artificial teeth, bone grafts, etc. Such known implants may consist for example of metal or plastic or another material having bio-compatible characteristics as well as sufficient mechanical stability. After healing, the implant may be removed by a further operation or may be left in the body where it remains permanently or, in case that bio-resorbable material is used for the implant, is gradually decomposed and replaced by vital tissue.
It is known in the art to provide implantation pins comprising a material which can be liquefied by application of ultrasonic vibrations. Therein, an implantation pin comprises a mouldable material such as a thermoplastic polymer which, upon applying ultrasonic vibrations, may be liquefied and then flows into adjacent tissue, for example into pores of an adjacent bone material, in order to fix the implantation pin into the target structure. Such implantation pin is described in a commonly assigned co-pending European patent application no. 07008122.9, published as EP 1982662A, as well as in the commonly assigned co-pending PCT application no. PCT/EP2008/000789 and U.S. Patent Publication No. 2008/0262517.
However, conventional implantation pins in which ultrasonic energy is used in order to liquefy mouldable material may suffer from various problems which complicate their use in actual surgical operations and which furthermore increase the costs inherent therewith.